HA full mesh core setup

[aero]

I'm looking for some advice on a fortigate HA active-active design.  I'm mostly concerned about the internal connectivity.  The HA pair would be connected to a core comprised of two layer 3 switches, trunked together (not stacked).

What I'm thinking needs to happen is this...

Each fortigate will have 2 connections, 1 to core1, 1 to core2

These 2 connections will be configured as "redundant interface" pairs

On the core switch side, all 4 ports will participate in a layer 3 vlan, running VRRP

OSPF or static routing between fortigates and core

That would seem like the most optimal setup from what I gather...suggestions?